1. Field of the Invention
The present invention relates generally to electromagnetic wave amplifiers and more particularly to a solid state electromagnetic wave amplifier used in the amplification of ultra high frequency electromagnetic waves at operating frequencies on the order of up to about 100 GHz.
2. Prior Art
The recent and remarkable development of Si-integrated circuits, has made the rapid processing of information available in all facets of modern life. New applications for this technology are constantly increasing, as is the demand for larger capacity, faster acting circuits which operate at high frequencies. This imposes a requirement for amplifiers capable of operating in a range up to the ultra high frequency. Furthermore, the trend in the electronics industry has been to incorporate more solid state components. At present, there still are two applications for vacuum tubes, which cannot be substituted for by solid state electronic elements. One is the Brown tube used for displays and the other is in ultra high frequency high power vacuum tubes such as the traveling wave tube. The latter utilizes the interaction between electrons traveling in a vacuum and the delayed wave of the electromagnetic field to produce a substantially higher power than produced by conventional tubes. This results because the interaction between the electrons and the electromagnetic field is not limited to a very small space like that of a triode tube, but the interaction is carried out across a broad surface with the propagation of the electromagnetic wave.
The traveling wave type amplification is expected to produce the same effects in its solid state version as compared with field effect devices. For this reason, solid state type traveling wave amplifiers have long been suggested as being desirable. Nevertheless, until the present invention, such amplifiers have not been reduced to practice.
The failure of the prior art is due to the fact that in conventional solid state type amplifiers using the interaction between the carrier wave of electrons of holes in the solid bulk material and the electromagnetic wave, the amplitude of the carrier wave which interacts with the electromagnetic field is decreased by the transverse diffusion of the carrier wave into the bulk of the solid body so that a sufficient interaction is not realized.
Accordingly, an invention of a solid state type electromagnetic wave amplifier having a structure capable of preventing such diffusion might enable one to achieve the hitherto unrealized solidification of ultra high frequency high power devices. Such a device may contribute to the miniaturization and weight reduction of microwave communication and radar equipment and may lead to drastic expansion of applicable fields such as microwave techniques.